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Biomedical subjects

J Kaldor

Publications and source records attributed to J Kaldor.

At least 55 records · Page 3Linked to original sources
PubMed1996

Hepatitis C virus infection in a large cohort of homosexually active men: independent associations with HIV-1 infection and injecting drug use but not sexual behaviour.

OBJECTIVE: To determine the prevalence and risk factors for hepatitis C virus (HCV) infection in a cohort of homosexually active men, with particular reference to assessing sexual transmission. DESIGN: Prevalence based on cross-sectional testing for HCV (c100 protein) antibody in a cohort using sera stored between 1984 and 1989, and assessment of risk factors using a case-control analysis based on questionnaire data from HCV positive and negative subjects. SUBJECTS/SETTING: 1038 homosexually active men who were participating in a prospective study established to identify risk factors for AIDS. They had been recruited through private and public primary care and sexually transmissible disease (STD) services in central Sydney. MAIN OUTCOME MEASURES: Prevalence of HCV antibody and its association with human immunodeficiency virus type 1 (HIV-1) infection and other STDs, number of sexual partners, sexual practices and recreational drug use. RESULTS: Overall, 7.6% of subjects tested were seropositive for HCV antibody. In univariate analysis, HCV infection was significantly associated with injecting drug use (IDU) (OR = 8.18, p < 0.0001) and HIV infection (OR = 3.14, p < 0.0001) and with self reported history of syphilis (OR = 1.88, p = 0.016), anogenital herpes (OR = 1.93, p = 0.017), gonorrhoea (OR = 2.43, p = 0.009) and hepatitis B (OR = 1.92, p = 0.010). In case control analysis, similar sexual behaviours (partner numbers and practices) were reported by HCV positive and HCV negative subjects except that HCV negative subjects more frequently reported engaging than HCV positive subject in unprotected receptive anal intercourse without ejaculation (OR = 0.61, p = 0.034), unprotected insertive (OR = 0.59, p = 0.039) and receptive (OR = 0.56, p = 0.016) oro-anal intercourse (rimming) and insertive fisting (OR = 0.48, p = 0.034). In multiple logistic regression analyses, only HIV-1 infection (OR = 3.18, p < 0.0001) and IDU in the previous six months (OR = 7.24, p < 0.0001) remained significantly associated with the presence of HCV antibody. CONCLUSIONS: IDU was the major behavioural risk factor for HCV infection. If sexual or another from of transmission did occur, it may have been facilitated by concurrent HIV-1 infection.

Adolescent↗
PubMed1996

The use of back projection to estimate HIV prevalence among pregnant women in Australia.

A statistical method similar to back projection was used to estimate the number of children infected with HIV perinatally from the number of children with AIDS due to perinatal HIV infection. By 31 December 1994 there were 18 children born in Australia and reported to have AIDS due to perinatal HIV infection. Based on these 18 AIDS cases, it was estimated that to the end of 1994 there were between 35 and 57 children born in Australia and infected with HIV perinatally, with a preferred estimate of 43 children. Assuming that the transmission rate of HIV from infected mothers to their babies was in the range 15 to 35%, it was estimated that the prevalence of HIV infection among women giving birth in Australia had increased from 0.03 per 1000 (range 0.02-0.07 per 1000) in 1983-1985 to 0.09 per 1000 (range 0.05-0.20 per 1000) in 1992-1994. This range for the prevalence of HIV infection among pregnant women in 1992-1994 was consistent with estimates of the prevalence from screening studies, and suggests that the prevalence of HIV infection in pregnant women in Australia remains low.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Preparation for phase III HIV vaccine efficacy trials: methods for the determination of HIV incidence.

OBJECTIVE: Accurate estimates of HIV incidence that reflect the effect of non-vaccine interventions (education, counselling, condom promotion, and possibly sexually transmitted disease treatment) and that may be provided in a Phase III vaccine efficacy trial, are needed so that vaccine trial population sample sizes can be accurately determined. In order to avoid delays in the implementation of efficacy trials, well characterized cohorts must also be developed and available to participate in such trials. We reviewed the potential study populations, the epidemiologic methods for the determination of HIV incidence (using open cohort, closed cohort, and seroprevalence data methods), and the need for the development of population cohorts in preparation for Phase III HIV vaccine efficacy trials. SETTING: Phase III trials in developed and developing countries. METHODS: Comparison of open and closed cohorts and those using seroprevalence data to estimate HIV incidence. RESULTS: Open and closed cohorts each have disadvantages and advantages. However, the open cohort may be more suitable for determining estimates of HIV incidence that reflect non-vaccine interventions and for the development of a well characterized cohort available to participate in efficacy trials. CONCLUSION: Careful preparation of research infrastructures and population cohorts will help ensure the successful conduct of scientifically and ethically sound HIV vaccine efficacy trials in the future.

AIDS Vaccines↗
PubMed1994

Risk factors for hepatitis C virus infection among injecting drug users in Sydney.

OBJECTIVE: To study risk factors for hepatitis C virus (HCV) infection in injecting drug users (IDUs) from central Sydney. SETTING AND SUBJECTS: All IDUs attending a primary health care facility in central Sydney between December 1991 and November 1992 who underwent HCV antibody testing. METHODS: Information was obtained retrospectively from client forms routinely completed at the time of medical consultation. Additional information on injecting history and practice was obtained from the registration forms of subjects who also attended the needle syringe exchange programme at the same health care facility. RESULTS: Of the 201 IDUs tested, 118 (59%) had HCV antibodies, which did not differ significantly between males and females. HCV prevalence increased significantly with age, being highest in IDUs who were aged 35 years or more (93%) and lowest in IDUs aged under 20 years (17%). HCV prevalence increased significantly with time since first injecting, from 26% for IDUs who had injected for less than 3 years to 94% for those who had injected for more than 10 years. HCV prevalence was also significantly higher in heterosexual IDUs as compared with homosexual male IDUs, and in opiate users as compared with stimulant users, even after adjustment for age and duration of injecting. HCV prevalence was strongly associated with exposure to hepatitis B virus, but was not associated with exposure to HIV. CONCLUSION: Recent HCV transmission indicates ongoing injecting risk behaviour despite HIV prevention efforts, and underlies the potential for increased transmission of HIV through the sharing of injecting equipment. Within the population of IDUs, those who are heterosexual or inject heroin appear to be at increased risk of HCV infection.

Adolescent↗
PubMed1993

HIV in the suburbs.

Explore the source record for details and available documents.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Non-melanoma skin cancer: ten years of cancer-registry-based surveillance.

The Tasmanian Cancer Registry carried out population-based surveillance of non-melanoma skin cancer (NMSC) from 1978 to 1987. A total of 8,651 NMSC were recorded in 7,160 individuals, representing an age-standardized rate of 161/100,000 per year. Ninety-four percent of cases were based on histological diagnosis. Incidence of basal-cell carcinoma (BCC) was higher than the incidence of squamous-cell carcinoma (SCC). The incidence of NMSC was twice as high in men as in women. Incidence increased substantially with age, more markedly for SCC than BCC. For most body sites, BCC was more frequent, but on highly exposed sites such as the backs of hands, lower limbs in women and ears in men, the incidence of SCC was higher. There was an overall increase of 7% per year in the age-standardized incidence rate of NMSC. The increase was more marked for BCC than for SCC, and was consistent across age groups and both sexes. A first NMSC during the study period was associated with a 12-fold increase among men and a 15-fold increase among women in the risk of development of a new NMSC within 5 years, when compared with the NMSC incidence recorded for the population as a whole.

Adult↗
PubMed1993

The acquired immunodeficiency syndrome in Australia: incidence 1982-1991.

OBJECTIVE: To describe the incidence of the acquired immunodeficiency syndrome (AIDS) in Australia between 1982 and 1991. DESIGN: State and Territory Health Departments notified new diagnoses of AIDS to the National AIDS Registry. Information reported for each case included sex, date of birth, date of AIDS diagnosis, presumed mode of exposure to the human immunodeficiency virus (HIV), and illness(es) on which the diagnosis of AIDS was based. RESULTS: To the end of March 1992, 3,160 cases of AIDS were reported as having been diagnosed between 1982 and the end of 1991. The cumulative incidence per head of population was about twice as high in New South Wales as in Australia as a whole. Over 97% of cases were in men, of whom 91% were adults or adolescents reporting homosexual contact. In women, 40% of cases were acquired through receipt of blood, blood products or tissue. The annual incidence of AIDS rose sharply until about 1988, but the annual rates of increase slowed in subsequent years. This trend was also apparent in cases acquired through sexual contact between men. In other exposure groups, numbers of cases were much smaller and trends less apparent. However, there was no indication of a similar levelling in AIDS incidence, except among blood transfusion recipients, in whom incidence may be declining. CONCLUSION: Transmission of HIV among people with AIDS in Australia has been overwhelmingly attributed to sexual contact between men. The annual incidence of cases attributed to sexual contact between men appears to be stabilising.

Acquired Immunodeficiency Syndrome↗
PubMed1993

HIV prevalence among IDUs in Australia: a methodological review.

A review was carried out of Australian studies which have measured the prevalence of HIV infection among injecting drug users (IDUs). The review considered published studies which had reported on serologically-determined HIV prevalence. There were five studies reported from specialized sexually-transmissible disease of HIV clinics, five studies reported from health services aimed at IDUs, three studies reported from other health services and one multi-centre behavioural study. The main findings from the studies were that HIV prevalence in IDUs has been low in Australia, apart from in male IDUs who also had homosexual contact. HIV prevalence ranged from 20 to 24% in male IDUs reporting homosexual contact and from 0 to 5% in other IDUs.The studies, while reflecting a range of research methodologies, are subject to a number of limitations. Most of the studies did not provide detailed analyses of HIV prevalence by age and sex or behavioural factors, and several studies used sampling frames which were not clearly defined. There is little available information on temporal trends in seroprevalence and geographical comparisons are rendered difficult by differences in the study methodology. Adoption of standardized, continuing seroprevalence surveys on IDUs would provide a better means of monitoring the occurrence of HIV infection in this group, which has been a key determinant of the course of the HIV epidemic in a number of Western countries.

Journal Article↗
PubMed1993

Duplicate reporting of AIDS cases between two neighbouring countries.

AIMS: To measure the extent and characteristics of cases of duplicate notification of diagnoses of Acquired Immunodeficiency Syndrome (AIDS) between Australia and New Zealand. METHODS: Cases of AIDS notified to the national AIDS registries in both Australia and New Zealand were identified, using date of birth and a name code. Cases determined to have been notified to both registries were analysed with respect to exposure category, country of birth and country of death. RESULTS: Twenty-six cases of AIDS were determined to be common to both registries, representing 1.1% of cases notified to the Australian registry and 11.1% of cases notified to the New Zealand registry. Exposure to HIV was attributed to male homosexual contact for all cases, and a history of injecting drug use was reported more frequently to the Australian registry for the cases in common. For the majority of cases notified to both registries, country of birth was recorded as New Zealand. Deaths following AIDS were reported as occurring in both countries with equal frequency.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Falling incidence of HIV infection in a cohort of clinic attenders.

It is widely accepted that changes in sexual behaviour in the mid-1980s drastically reduced the spread of human immunodeficiency virus (HIV) through male homosexual contact in Western countries, but documentation of changes in infection rates has been based on observation of subjects enrolled in cohort studies, who may be highly selected and motivated. In this study, the incidence of HIV seroconversion was investigated among people attending a major site of HIV testing, counselling and patient care in Sydney. Over the period March 1985 to June 1990, 2,301 people were tested for HIV antibody on more than one occasion, following a negative result at the first test. On the basis of subsequent tests, 107 were found to have seroconverted during the study period, including 91 men who reported homosexual or bisexual contact as their only exposure to HIV. Overall, the incidence rate of HIV infection among men reporting homosexual or bisexual contact was 404 per 100 person-years of follow-up. Under various methods of calculation, the incidence was estimated to have declined between 1985 and 1989-1990. However, there was continuing HIV seroconversion in 1989-1990 and no indication of declining incidence in younger men. The fall in HIV incidence documented in this study supports the role of HIV prevention programs aimed at homosexual and bisexual men.

Adult↗
PubMed1993

Kaposi's sarcoma as a sexually transmissible infection: an analysis of Australian AIDS surveillance data. The National HIV Surveillance Committee.

OBJECTIVE: To further examine the hypothesis that Kaposi's sarcoma (KS) among people with AIDS is caused by a sexually transmissible infectious agent. DESIGN: Analysis of Australian AIDS surveillance data for the period 1982-1991 by sex, age, exposure category, country of birth, year and place of diagnosis. MAIN OUTCOME MEASURES: Percentage of people with AIDS who had KS. RESULTS: In Australia, by November 1991, 17.2% (527 out of 3067) of individuals with AIDS aged > or = 13 years had presented with KS as their AIDS-defining illness: men, 17.6% (524 out of 2977); women, 3.4% (three out of 87) (P < 0.001). KS was predominantly reported in people aged 20-49 years and there were no cases in children < 13 years of age. In general, KS was more common in those who had acquired HIV by sexual contact rather than parenterally. Among people aged > or = 13 years, the proportion with KS ranged from 0.0% (none out of 41) in men with haemophilia to 1 Iford 9.0% (483 out of 2542) in men reporting homosexual contact. Between 1984-1985 and 1990-1991, the percentage of men with AIDS reporting homosexual contact who presented with KS declined from 30% (37 out of 124) to 15% (145 out of 995) (chi 2 for a linear trend, P < 0.001). For men with AIDS reporting homosexual contact, the percentage with KS in New South Wales and Victoria (20.3%) was higher than in the other States and Territories (12.5%) (P < 0.001). New South Wales and Victoria have also reported the highest incidence of AIDS in Australia. CONCLUSION: The epidemiological characteristics of KS among people with AIDS in Australia are broadly consistent with those reported from the United States and Europe. This provides further evidence that KS may be caused by a sexually transmissible infectious agent. The nature of the infectious agent and its mode of transmission have yet to be determined.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Epidemiological pattern of HIV infection in Australia.

Human immunodeficiency virus (HIV) infection in Australia has been transmitted primarily through sex between men. Multiple sources of information, including backprojection from AIDS cases and longitudinal studies involving repeat testing for HIV antibody, indicate that the rate of HIV transmission through sex between men reached a peak in 1983-1984 and declined rapidly in subsequent years. However, there is also evidence that HIV infection continues to be transmitted through sex between men in Australia. Intravenous drug use has been reported by only a small proportion of people diagnosed with HIV infection in Australia, and surveys of intravenous drug users have found a low rate of infection apart from in men who had homosexual contract. Behavioral studies have found that sharing of injecting equipment has continued, suggesting that low infection rates may be a consequence of sharing patterns. Heterosexual transmission seems to have been infrequent in Australia, perhaps because of the low rate of HIV infection in intravenous drug users.

Australia↗
PubMed1992

Long-term symptomless HIV-1 infection in recipients of blood products from a single donor.

There have been reported cases of long-term symptomless human immunodeficiency virus type 1 (HIV-1) infection, but it is not clear whether the benign course of infection was due to host, viral, or other unknown factors. During follow-up of subjects with transfusion-acquired HIV-1 infection in New South Wales, Australia, we identified a group of 6 subjects who had been infected through a single common donor. We were therefore able to study the contributions of various factors to the course of infection. Throughout follow-up (range 6.8-10.1 years after infection), 5 of the recipients and the donor (last follow-up 10.2 years after infection of the first recipient) remained clinically free of symptoms, with normal CD4 cell counts and no p24 antigenaemia. HIV-1 was isolated from only 1 recipient; the isolate did not induce syncytia in a SUPT1 co-culture assay and had a limited in-vitro host range. 1 infected recipient (who had received extensive immunosuppressive treatment for systemic lupus erythematosus) developed Pneumocystis carinii pneumonia and died 4.3 years after infection. The frequency of progression to AIDS or a CD4 cell count below 0.50 x 10(9)/l was significantly lower among the 6 subjects with a common donor (1/6) than among 101 other HIV-infected transfusion recipients for whom data from 7 years of follow-up were available (94/101; p less than 0.0001). These findings suggest that the subjects were infected by a less virulent strain of HIV-1. The identification of this group of subjects should stimulate a search for other similar groups, which will provide important information on the immunopathogenesis of HIV-1 disease.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Colon cancer in Argentina. I: Risk from intake of dietary items.

A case-control study has been conducted to investigate the relationship between dietary components and risk of colon cancer in the La Plata area of Argentina. Cases are 110 patients newly diagnosed with colon cancer in 10 major hospitals between 1985 and 1986. Two neighbourhood controls per case were individually matched by age, sex and place of residence. Personal interviews elicited information on frequency of consumption of 140 food items during the 5-year period up to 6 months prior to interview. Risk is analyzed by quartiles of individual food items and groups of items. Multivariate conditional logistic regression modelling indicates that consumption of eggs is associated with increased risk for colon cancer (odds ratios by quartile: 1.0, 1.58, 2.02, 4.66), as are some dairy products (ORs of 1.93 for the highest quartile of consumption of cheese). Intake of vegetables, fish and poultry is associated with statistically significant decreasing risk (ORs of 0.075, 0.39 and 0.39, for the highest categories of consumption of vegetables, fish and poultry, respectively). The risk for red meat does not consistently increase as consumption increases. Risks are not altered by the inclusion of potential confounders such as education or body mass index. These findings confirm those of several previous studies and are of particular interest, since the Argentinean diet typically includes a high intake of red meat.

Adult↗